Vulnerability Details CVE-2025-39840
In the Linux kernel, the following vulnerability has been resolved:
audit: fix out-of-bounds read in audit_compare_dname_path()
When a watch on dir=/ is combined with an fsnotify event for a
single-character name directly under / (e.g., creating /a), an
out-of-bounds read can occur in audit_compare_dname_path().
The helper parent_len() returns 1 for "/". In audit_compare_dname_path(),
when parentlen equals the full path length (1), the code sets p = path + 1
and pathlen = 1 - 1 = 0. The subsequent loop then dereferences
p[pathlen - 1] (i.e., p[-1]), causing an out-of-bounds read.
Fix this by adding a pathlen > 0 check to the while loop condition
to prevent the out-of-bounds access.
[PM: subject tweak, sign-off email fixes]
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 5.7%
CVSS Severity
CVSS v3 Score 7.1
Products affected by CVE-2025-39840
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cpe:2.3:o:linux:linux_kernel:6.14
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cpe:2.3:o:linux:linux_kernel:6.14.1
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cpe:2.3:o:linux:linux_kernel:6.14.10
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cpe:2.3:o:linux:linux_kernel:6.14.11
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cpe:2.3:o:linux:linux_kernel:6.14.2
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cpe:2.3:o:linux:linux_kernel:6.14.3
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cpe:2.3:o:linux:linux_kernel:6.14.4
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cpe:2.3:o:linux:linux_kernel:6.14.5
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cpe:2.3:o:linux:linux_kernel:6.14.6
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cpe:2.3:o:linux:linux_kernel:6.14.7
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cpe:2.3:o:linux:linux_kernel:6.14.8
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cpe:2.3:o:linux:linux_kernel:6.14.9
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cpe:2.3:o:linux:linux_kernel:6.15
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cpe:2.3:o:linux:linux_kernel:6.15.1
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cpe:2.3:o:linux:linux_kernel:6.15.10
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cpe:2.3:o:linux:linux_kernel:6.15.11
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cpe:2.3:o:linux:linux_kernel:6.15.2
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cpe:2.3:o:linux:linux_kernel:6.15.3
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cpe:2.3:o:linux:linux_kernel:6.15.4
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cpe:2.3:o:linux:linux_kernel:6.15.5
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cpe:2.3:o:linux:linux_kernel:6.15.6
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cpe:2.3:o:linux:linux_kernel:6.15.7
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cpe:2.3:o:linux:linux_kernel:6.15.8
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cpe:2.3:o:linux:linux_kernel:6.15.9
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cpe:2.3:o:linux:linux_kernel:6.16
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cpe:2.3:o:linux:linux_kernel:6.16.1
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cpe:2.3:o:linux:linux_kernel:6.16.2
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cpe:2.3:o:linux:linux_kernel:6.16.3
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cpe:2.3:o:linux:linux_kernel:6.16.4
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cpe:2.3:o:linux:linux_kernel:6.16.5
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cpe:2.3:o:linux:linux_kernel:6.17